In the context of gender, passing refers to a person's ability to be regarded at a glance to be either a cisgender man or a cisgender woman.[1] Typically, passing involves a mixture of physical gender cues (for example, hair style or clothing) as well as certain behavioral attributes that tend to be culturally associated with a particular gender. Irrespective of a person's presentation, many experienced crossdressers assert that confidence is far more important for passing than the physical aspects of appearance.[2] Groups of people whose members may be concerned with passing are crossdressers, drag queens and drag kings, trans men, trans women and those who identify as a third, non-binary, or genderqueer identity.

Gender attribution is the process by which an observer decides which gender they believe another person to be.[3] Once an observer makes an attribution of the gender of a person, it can be difficult to make them change their mind and see the person as another gender.[4]

In black culture, the failure to pass as the desired gender is referred to as being read.[5] (/rɛd/) In this context, "read" is used as a verb. The event of being read is known as "a read". (/riːd/) In this context, read is used as a noun. It can also be called "being clocked."[6]

A person is far more likely to be able to read someone of their own race but less likely to read someone of a different race. It is generally accepted that this is because gender cues within one's own race are more readily recognized than gender cues of other races. Some people opt to leave their country of origin, because gender cues can vary greatly between countries. Vocal range, physical build, hairline shape, facial structure, demeanor and clothing styles are just some of the reasons cited.[7]

Passing is much more than physical appearance, there is a spectrum of difference in the same gender, height, bone structure, appearance of having or lack of having an Adam's apple, so the mind does not just rely on the looks alone. Mannerisms and vocabulary are even more important. The mind picks up these inconsistencies or supporting traits, in so supporting a person's appearance (passing) or not (being read). How a person is dressed, or clothing that is out of place for the surroundings, will draw attention. A mini skirt, mink coat and knee high boots even on a cis woman in a supermarket will focus one's attention on her, leaving her open to observation for other tell-tale traits.

Depending on a person's presentation, anyone may be able to read them. What is more important than whether a person is read or not is how others react if they do read that person. It is suggested by some researchers that many trans people who believe that they are passing are in fact being read by many observers, but the observers do nothing confrontational and hence the trans person is not even aware that they were read.[4]

It is also notable that "reading" and "being read" have the alternate meaning of insulting and being insulted in the context of Ball culture.[8] Very often the subject of the read is a flaw that would result in not passing. The term used for passing in Ball culture is "realness".[9]

The term stealth is used to refer to a person who passes as their desired gender at all times, and who has broken contact with everybody who knew their gender history. Thus, everybody around them is unaware that they were not always presenting as the current gender, and they are effectively invisible within the population of their current gender. In order to live in stealth,[6] an individual has to be extremely passable. People may also choose to be stealth in some parts of their lives and not other, disconnected parts (for instance, being stealth at work, but openly transgender amongst friends).

Jennie Irene Hodgers, dressed as Albert Cashier, was an Irish-born soldier in the Union Army during the United States' Civil War.

Historically, there have been circumstances wherein people have impersonated the opposite sex for reasons other than gender identity. The most common reasons for women disguising themselves as men were so that they could go into battle as soldiers, or in order to work in male-dominated professions that would not hire women.

Two of the most famous examples of women who disguised themselves as men to fight in battle are Joan of Arc, who fought for France against the English during the Hundred Years' War, and Hua Mulan, who, according to legend, took her elderly father's place in the Chinese army.

In Stone Butch Blues, Leslie Feinberg wrote about working class, butchlesbians in the 1960s who chose to pass as men in order to find jobs that would enable them to support their families.[10] While the 1993 novel is fiction, there are females, including Feinberg, who took testosterone in this era for these reasons. Factory jobs, in particular, usually only paid men a living wage that could also support a partner and children. Some of these passing women later identified as transgender, while others stopped taking hormones and returned to a butch female presentation once gains made by feminists allowed for better employment opportunities.[11][12][13]

American band leader Billy Tipton had a successful career as a jazz musician in the 1930s through the 1970s. Tipton was from the conservative Midwest. The world at large only discovered Tipton was female-bodied after his death.[14][15][16]

Those performers (drag kings and drag queens) who are open about their natal sex are not typically referred to as "passing", even though some may be able to do so. Many cross-dressers who venture out into public areas do try to pass. Many transsexuals live and work in their gender and seek to be fully accepted as a member of that gender, rather than that which they were assigned. Therefore, passing is not just an option but is seen as a necessity by many.

Transgender people who do not describe themselves as either cross dressers, transvestites, or transsexuals may have different attitudes towards passing. For example, they might not try to pass at all, they may engage in genderfuck (sending consciously mixed signals), or they might be able to pass, but do not hide the fact that they are transgender. Personal views on passing and the desire or need to pass are independent of whether an individual has had medical treatment or has legally changed their gender.

In the transgender and crossdressing communities, those that cannot pass may sometimes view those that pass with jealousy. Because of this, there may be a tendency for some of those who pass to avoid those who are easily read. There is the perception among many that when one person is read, anyone with that person will be assumed to be transgender or crossdressing, by association.

It should be noted that the use of the term "passing" regarding sexual orientation denotes "hiding" one's identity, where use among gender-variant people (as noted above) signals acceptance and concordance with one's internal sense of or desired gender identity. However, for this reason, and because transgender persons who come to live full-time in their desired gender/sex identity often recognize their previous attempts to conceal their identity and be accepted in socially-accepted and designated roles as the real artifice they constructed and protected, some have begun to instead call their previous gender-normative and concealing behaviours as "passing".[citation needed]

In the television series Hell on Wheels, season 5, Cullen Bohannon discovers the bilingual Chinese railroad worker known as Tao's son, Ah Fong, is actually Tao's daughter, Mei Fong. Mei pretended to be male both to escape being married off against her will and to work on the railroad, which hired men only.